MOVEMENT OF HEAVY METALS IN THE ECO‑ENVIRONMENT THROUGH TROPHIC LEVELS OF FOOD CHAIN

Kaiser Jamil, Biology and Biotechnology Division, Indian Institute of Chemical Technology, Hyderabad. A.P. India.

Abstract: In our investigation on biotransfer of heavy metals through the trophic levels of food chain we report, their interference in various biochemical parameters at the second level of consumers. The route of the movement of heavy metals in the ecoenvironment is as follows: first the uptake of. soluble metal ions like Cr., Cd, Pb and Zn from the aquatic medium (water). Then to the aquatic plants via the roots and then by active transport to the stems and leaves (I" level) and from the aquatic plants to the insects which consume these plants as their food (zd level). Further the 3ra level of biotransfer in the biosystem is through the trophic levels of food chain is by the predators (higher organisms) which prey upon these metal contaminated insects. The movement of these toxicants (heavy metals) from one biosystem to another in the eco‑environment is an important phenomenon, as its leaves a trail of changes in the organisms through which it passes. The biochemical changes and the response of the plants to the presence of the heavy metals in their system was seen and characterized by the changes in enzymes like (SOD & PPO) and the interruptions in protein synthesis and photosynthesis. While the biochemical changes in the insects related to its defense enzymes like ALAT & AAT, besides its effects on macromolecules. Even though the content or the concentration of the heavy metals decreased as we go higher in the trophic levels of food chain, but the biomagnification effect increased. Hence, it is concluded that metals, which can neither be created nor destroyed, appear to transform the environments and biosystems through which they transit, most of the time they are hazardous effects.